ANATOMY CHAPTER 18

The 12 pairs of cranial nerves are so named because they pass through various ________ in the bones of the cranium and arise from the brain inside the cranial cavity. - part of the PNS

foramina

The __________, stria terminalis, stria medullaris, medial forebrain bundle, and mammillothalamic tract are linked by bundles of interconnecting myelinated axons.

fornix

in the frontal cortex is sometimes included in the premotor area. It controls voluntary scanning movements of the eyes—like those you just used in reading this sentence

frontal eye field area (8)

Each cerebral hemisphere can be further subdivided into several lobes. The lobes are named after the bones that cover them:

frontal, parietal, temporal, and occipital lobes

Sensory impulses related to both __________ and __________ senses arrive at the hypothalamus, as do impulses from receptors for vision, taste, and smell

somatic and visceral

A person with damage in the primary visual area would be blind in at least part of his visual field, but a person with damage to a ______________ might see normally yet be unable to recognize a friend.

visual association area

located in the occipital lobe, receives sensory impulses from the primary visual area and the thalamus. It relates present and past visual experiences and is essential for recognizing and evaluating what is seen. - allows you to recognize an object

visual association area (18 and 19)

By the time a person reaches age 80, the brain weighs about ____ less than it did in young adulthood.

7%

The hypothalamus controls and integrates activities of the _____, which regulates contraction of smooth and cardiac muscle and the secretions of many glands. -Axons extend from the hypothalamus to sympathetic and parasympathetic nuclei in the brainstem and spinal cord - is a major regulator of visceral activities, including heart rate, movement of food through the gastrointestinal tract, and contraction of the urinary bladder.

ANS

Speaking and understanding language - helps us to form words

Brocas speech area (44 and 45)

___________________ (HD) is an inherited disorder in which the caudate nucleus and putamen degenerate, with loss of neurons that normally release GABA or acetylcholine.

Huntington disease

People who have _________ experience repetitive thoughts (obsessions) that cause repetitive behaviors (compulsions) that they feel obligated to perform. For example, a person with _________ might have repetitive thoughts about someone breaking into the house; these thoughts might drive that person to check the doors of the house over and over again (for minutes or hours at a time) to make sure that they are locked.

OCD

broad region in the left temporal and parietal lobes, interprets the meaning of speech by recognizing spoken words. It is active as you translate words into thoughts. - ppl who are bilingual

Wernikes area (22, 39, 40)

a small region superior and posterior to the thalamus, consists of the pineal gland and habenular nucle

epithalamus

The _____________ is composed of several groups of neurons located close to the tail of the caudate nucleus.

amygadala

Two nuclei of the thalamus, the ___________ and the______________, participate in limbic circuits.

anterior nucleus medial nucleus

deal with more complex integrative functions such as memory, emotions, reasoning, will, judgment, personality traits, and intelligenc

association areas

contain axons that conduct nerve impulses between gyri in the same hemisphere.

association tracts

Deep within each cerebral hemisphere are three nuclei (masses of gray matter) that are collectively termed the

basal nuclei

In addition to influencing motor functions, the _____________ have other roles. They help initiate and terminate some cognitive processes, such as attention, memory, and planning, and may act with the limbic system to regulate emotional behaviors.

basal nuclei

The ____________ receive input from the cerebral cortex and provide output to motor parts of the cortex via the medial nuclei and ventral group nuclei of the thalamus - have extensive connections with one another. A major function of the is to help regulate initiation and termination of movements.

basal nuclei

Activity of neurons in the putamen precedes or anticipates _______________; activity of neurons in the caudate nucleus occurs prior to eye movements.

body movements

At any instant, brain neurons are generating millions of action potentials

brain waves

The third of the basal nuclei is the _________________, which has a large "head" connected to a smaller "tail" by a long comma-shaped "body."

caudate nucleus

The ________________ separates the frontal lobe from the parietal lobe.

centeal sulcus

The hemispheres consist of an outer rim of gray matter, an internal region of cerebral white matter, and gray matter nuclei deep within the white matter. The outer rim of gray matter is the _______________. the _______________ contains billions of neurons arranged in layers. Deep to the _____________ lies the cerebral white matter.

cerebral cortex

By far the largest portion of the human brain, the cerebrum consists of the ________________ and the basal nuclei. The right and left halves of the cerebrum, called _________________, are separated by a deep groove called the longitudinal fissure that is occupied by the falx cerebri

cerebral hemispheres

is a motor disorder that results in the loss of muscle control and coordination; it is caused by damage of the motor areas of the brain during fetal life, birth, or infancy. Radiation during fetal life, temporary lack of oxygen during birth, and hydrocephalus during infancy may also cause cerebral palsy.

cerebral palsy ( CP)

The ___________________ consists primarily of myelinated axons in three types of tracts

cerebral white matter

is the "seat of intelligence." It provides us with the ability to read, write, and speak; to make calculations and compose music; and to remember the past, plan for the future, and imagine things that have never existed before.

cerebrum

A key sign of HD is ______________, in which rapid, jerky movements occur involuntarily and without purpose. Progressive mental deterioration also occurs. Symptoms of HD often do not appear until age 30 or 40. Death occurs 10 to 20 years after symptoms first appear.

chorea

The so-called limbic lobe is a rim of cerebral cortex on the medial surface of each hemisphere. It includes the ___________ , which lies above the corpus callosum, and the ___________________ which is in the temporal lobe below.

cingulate gyrus parahippocampal gyrus

Parts of the diencephalon, called _______________________ because they lie in the wall of the third ventricle, can monitor chemical changes in the blood because they lack a blood-brain barrier. - coordinate homeostatic activities of the endocrine and nervous systems, such as the regulation of blood pressure, fluid balance, hunger, and thirst. -sites of entry into the brain of HIV, the virus that causes AIDS.

circumventricular organs

is a thin sheet of gray matter situated lateral to the putamen. It is considered by some to be a subdivision of the basal nuclei. -The function of the this in humans has not been clearly defined but it may be involved in visual attention.

claustrum

contain axons that conduct nerve impulses from gyri in one cerebral hemisphere to corresponding gyri in the other cerebral hemisphere.

commissural tracts

integrates sensory information from the association areas and impulses from other areas, allowing the formation of thoughts based on a variety of sensory inputs. It then transmits signals to other parts of the brain for the appropriate response to the sensory signals it has interpreted.

common integrative area (5, 7)

If the temperature of blood flowing through the hypothalamus is above normal, the hypothalamus directs the autonomic nervous system to stimulate activities that promote heat loss. When blood temperature is below normal, the hypothalamus generates impulses that promote heat production and retention.

control of body temperature

The hemispheres are connected internally by the ______________, a broad band of white matter containing axons that extend between the hemispheres at the floor of the longitudinal fissure

corpus callosum

Three important groups of commissural tracts are the:

corpus callosum (the largest fiber bundle in the brain, containing about 300 million fibers), anterior commissure, and posterior commissure.

Together, the lentiform and caudate nuclei are known as the _____________. -refers to the striated (striped) appearance of the internal capsule as it passes among the basal nuclei.

corpus striatum

once HIV is in the brain what does it cause?

dementia and other neurological disorders

The _____________ lies between the hippocampus and parahippocampal gyrus.

dentate gyrus

The deepest grooves between folds are known as ___________; the shallower grooves between folds are termed ________

fissures sulci

useful in the study of normal brain functions, such as changes that occur during sleep, and in diagnosis of a variety of brain disorders, such as epilepsy, tumors, metabolic abnormalities, sites of trauma, and degenerative diseases. - can record brain waves

electrocephalogram

The limbic system is sometimes called the "______________" because it plays a primary role in a range of emotions, including pain, pleasure, docility, affection, and anger. -also involved in olfaction and memory

emotional brain

The ____________ helps regulate the muscle tone required for specific body movements. The basal nuclei also control subconscious contractions of skeletal muscles

globus pallidus

Two of the basal nuclei are side-by-side, just lateral to the thalamus. They are the _______________, which is closer to the thalamus, and the __________ which is closer to the cerebral cortex.

globus pallidus putamen

During embryonic development, when brain size increases rapidly, the gray matter of the cortex enlarges much faster than the deeper white matter. As a result, the cortical region rolls and folds upon itself. The folds are called:

gyri or convolutions

The ____________, are involved in olfaction, especially emotional responses to odors such as a loved one's cologne or Mom's chocolate chip cookies baking in the oven.

habenular nuclei

functional asymmetry of the brain

hemispheric lateralization

The _____________ is a portion of the parahippocampal gyrus that extends into the floor of the lateral ventricle.

hippocampus

The hypothalamus controls many body activities and is one of the major regulators of _______________.

homeostasis

receive and interpret sensory impulses

sensory areas

Second, axons extend from the paraventricular and supraoptic nuclei through the __________ into the posterior lobe of the pituitary. The cell bodies of these neurons make one of two hormones (oxytocin or antidiuretic hormone). Their axons transport the hormones to the posterior pituitary, where they are released.

infundibulum

branchial moror axons

innervate skeletal muscles that develop from the pharyngeal (branchial) arches. These neurons leave the brain through the mixed cranial nerves.

A fifth part of the cerebrum, the ____________, cannot be seen at the surface of the brain because it lies within the lateral cerebral sulcus, deep to the parietal, frontal, and temporal lobes

insula

An example of a projection tract is the _______________, a thick band of white matter that contains both ascending and descending axons

internal capsule

The ___________________ separates the frontal lobe from the temporal lobe. The _________________ separates the parietal lobe from the occipital lobe.

lateral cerebral sulcus parieto-occipital sulcus

which actually arise from the cervical spinal cord and innervate the trapezius and sternocleidomastoid muscles.

lateral mesodermal motor axons

Together, the globus pallidus and putamen are referred to as the _____________

lentiform nucleus

Encircling the upper part of the brainstem and the corpus callosum is a ring of structures on the inner border of the cerebrum and floor of the diencephalon that constitutes the

limbic system

As mentioned previously, the most prominent fissure, the _____________, separates the cerebrum into right and left halves called cerebral hemispheres.

longitudinal fissure

The ___________ of the hypothalamus are two round masses close to the midline near the cerebral peduncles.

mammilary bodies

First, hypothalamic hormones are released into capillary networks in the ______________. The bloodstream carries these hormones directly to the anterior lobe of the pituitary, where they stimulate or inhibit secretion of anterior pituitary hormones.

median eminence

The pineal gland is part of the endocrine system because it secretes the hormone -It induces sleep, serves as an antioxidant, and inhibits reproductive functions in certain animals. As more is liberated during darkness than in light, this hormone is thought to promote sleepiness. When taken orally, it also appears to contribute to the setting of the body's biological clock by inducing sleep and helping the body to adjust to jet lag.

melatonin

the process by which information acquired through learning is stored and retrieved - must produce functional and structural change sin the bran to become this

memory

One portion of the limbic system, the hippocampus, is seemingly unique among structures of the central nervous system—it has cells reported to be capable of ____________. Thus, the portion of the brain that is responsible for some aspects of memory may develop new neurons, even in the elderly.

mitosis

The remaining five cranial nerves (V, VII, IX, X, and XI) are mixed nerves—they contain axons of both sensory neurons entering the brainstem and motor neurons leaving the brainstem.

mixed nerves

initiate movements

motor areas

Four cranial nerves (III, IV, VI, and XII) are classified as _______ because they contain only axons of motor neurons as they leave the brainstem. The cell bodies of motor neurons lie in nuclei within the brain

motor nerves

The brain grows rapidly during the first few years of life. Growth is due mainly to an increase in the size of ________ already present, the proliferation and growth of neuroglia, the development of dendritic branches and synaptic contacts, and continuing myelination of axons.

neurons

somatic motor axons

nnervate skeletal muscles that develop from prechordal mesoderm (extrinsic eye muscles) and occipital somites (tongue muscles). These neurons exit the brain through four motor cranial nerves (III, IV, VI, and XII).

The _________________ are flattened bodies of the olfactory pathway that rest on the cribriform plate.

olfactory bulbs

Other receptors within the hypothalamus itself continually monitor ______________, ____________, certain hormone concentrations, and the temperature of blood.

osmotic pressure blood glucose level

Disorders of the basal nuclei can affect body movements, cognition, and behavior. Uncontrollable shaking (tremor) and muscle rigidity (stiffness) are hallmark signs of ________________ (PD). In this disorder, dopamine-releasing neurons that extend from the substantia nigra to the putamen and caudate nucleus degenerate.

parkinsons disease

In response to visual input from the eyes (retina), the SCN stimulates the ____________ to secrete the hormone melatonin in a rhythmic pattern, with low levels of melatonin secreted during the day and significantly higher levels secreted at night. The changing levels of melatonin, in turn, promote rhythmic changes in sleep, wakefulness, hormone secretion, and body temperature.

pineal gland

is about the size of a small pea and protrudes from the posterior midline of the third ventricle

pineal gland

Another major gyrus, the ____________________, which is located immediately posterior to the central sulcus, contains the primary somatosensory area of the cerebral cortex.

post central gyrus

The ____________ are located within the septal area formed by the regions under the corpus callosum and the paraterminal gyrus (a cerebral gyrus).

septal nuclei

A major gyrus, the ___________—located immediately anterior to the central sulcus—contains the primary motor area of the cerebral cortex.

precentral gyrus

concerned with the makeup of a person's personality, intellect, complex learning abilities, recall of information, initiative, judgment, foresight, reasoning, conscience, intuition, mood, planning for the future, and development of abstract ideas

prefrontal cortex (9-12)

deals with learned motor activities of a complex and sequential nature. It generates nerve impulses that cause specific groups of muscles to contract in a specific sequence, as when you write your name. The premotor area also serves as a memory bank for such movements.

premotor area (6)

located in the superior part of the temporal lobe near the lateral cerebral sulcus, receives information from auditory receptors and is involved in auditory perception

primary auditory area (41 and 42)

, located at the base of the postcentral gyrus superior to the lateral cerebral sulcus in the parietal cortex, receives impulses for taste and is involved in gustatory perception.

primary gustatory area (43)

-Each region in the primary motor area controls voluntary contractions of specific muscles or groups of muscles -Electrical stimulation of any point in the __________________ causes contraction of specific skeletal muscle fibers on the opposite side of the body

primary motor area (4)

located on the medial aspect of the temporal lobe (not visible) , receives impulses for smell and is involved in olfactory perception.

primary olfactory area (28)

receives nerve impulses for touch, proprioception (joint and muscle position), pain, itch, tickle, and thermal sensations. A "map" of the entire body is present here -> pinpoint the areas where sensations originate, so that you know exactly where on your body to swat at that mosquito.

primary somatosensory area (1,2,3)

located at the posterior tip of the occipital lobe mainly on the medial surface (next to the longitudinal fissure), receives visual information and is involved in visual perception.

primary visual area (17)

The hypothalamus __________ and has two important connections with the pituitary gland, an endocrine gland located inferior to the hypothalamus.

production of hormones

contain axons that conduct nerve impulses from the cerebrum to lower parts of the CNS (thalamus, brainstem, or spinal cord) or from lower parts of the CNS to the cerebrum.

projection tract

The suprachiasmatic nucleus establishes patterns of awakening and sleep that occur on a circadian (daily) rhythm. This nucleus receives input from the eyes (retina) and sends output to other hypothalamic nuclei, the reticular formation, and the pineal gland.

regulation of circadian rhythm and state of consciousness

The hypothalamus regulates food intake through the arcuate and paraventricular nuclei. It also contains a thirst center. When certain cells in the hypothalamus are stimulated by rising osmotic pressure of the extracellular fluid, they cause the sensation of thirst. The intake of water by drinking restores the osmotic pressure to normal, removing the stimulation and relieving the thirst.

regulation of eating and drinking

Together with the limbic system, the hypothalamus participates in expressions of rage, aggression, pain, and pleasure, and the behavioral patterns related to sexual arousal.

regulation of emotional and behavioral patterns

excess dopamine activity in the brain causes a person to experience delusions, distortions of reality, paranoia, and hallucinations.

schizophrenia

This area permits you to determine the exact shape and texture of an object without looking at it, to determine the orientation of one object with respect to another as they are felt, and to sense the relationship of one body part to another - storage of memories from past sensory experiences

somatosensory assocaition area ( 5 and 7)

what are association tracts?

somatosensory assocation area wernikes area prefrotnal cortex -visual association area - auditory association area - common integrative area

Three cranial nerves (I, II, and VIII) carry axons of sensory neurons into the brain and thus are called

special sensory nerves

Nearby structures that are functionally linked to the basal nuclei are the ________________ of the midbrain and the subthalamic nuclei of the diencephalon

substantia nigra

Melatonin helps regulate circadian rhythms, which, as you have just learned, are established by the _____________________ of the hypothalamus

suprachiasmatic nucleus (SCN)

Although the number of neurons present does not decrease very much, the number of ____________ declines. Associated with the decrease in brain mass is a decreased capacity for sending nerve impulses to and from the brain. As a result, processing of information diminishes, conduction velocity decreases, voluntary motor movements slow down, and reflex times increase.

synaptic contacts

is a disorder that is characterized by involuntary body movements (motor tics) and the use of inappropriate or unnecessary sounds or words (vocal tics). Although the cause is unknown, research suggests that this disorder involves a dysfunction of the cognitive neural circuits between the basal nuclei and the prefrontal cortex.

tourette syndrome